Backlight unit with heat-radiating plates soldered to terminals and liquid crystal display device using the backlight unit

Abstract

A backlight unit includes a light guide plate, a fluorescent tube having terminals at both ends thereof and disposed along a side surface of the light guide plate, a reflector plate fitted to a principal surface on one side of the light guide plate, and a reflector film fitted to the light guide plate so as to cover the fluorescent tube. Leads are soldered respectively to the terminals of the fluorescent tube, and heat-radiating plates are co-soldered to the solder portions. A temperature rise at the solder portion can be restrained by the heat-radiating plate, so that deterioration of the solder portions can be restrained, and contact failure between the terminals of the fluorescent tube and the leads due to deterioration of the solder portions can be prevented.

What is claimed is:  
     
       1. A backlight unit comprising: 
       a light guide plate,  
       a fluorescent tube having terminals at both ends thereof and disposed along a side surface of said light guide plate,  
       a reflector plate mounted to a one surface of said light guide plate,  
       a reflector film mounted to said light guide plate so as to cover said fluorescent tube,  
       a pair of leads soldered respectively to said terminals, and  
       a heat-radiating plate provided at at least one of soldered portions between said terminals and said leads.  
     
     
       2. A backlight unit as set forth in  claim 1 , wherein said heat-radiating plate is co-soldered to said soldered portion between said terminal and said lead. 
     
     
       3. A backlight unit as set forth in  claim 2 , wherein said heat-radiating plate is wavy in shape. 
     
     
       4. A backlight unit as set forth in  claim 2 , wherein said heat-radiating plate is cylindrical in shape. 
     
     
       5. A liquid crystal display device comprising: 
       a liquid crystal panel,  
       a light guide plate mounted to a one surface of said liquid crystal panel,  
       a fluorescent tube having terminals at both ends thereof and disposed along a side surface of said light guide plate,  
       a reflector plate mounted to a principal surface of said light guide plate on the side opposite to said liquid crystal panel,  
       a reflector film mounted to said light guide plate so as to cover said fluorescent tube,  
       a pair of leads soldered respectively to said terminals, and  
       a heat-radiating plate provided at at least one of soldered portions between said terminals and said leads.  
     
     
       6. A liquid crystal display device as set forth in  claim 5 , wherein said heat-radiating plate is co-soldered to said soldered portion between said terminal and said lead.